KR100755010B1 - Lighting device - Google Patents

Abstract

A lighting device is provided to uniformly diffuse the light over the whole surface of a diffusion plate by scattering the light emitted from a light source through bubbles of the diffusion plate and to transmit the light of the light source at high light transmissivity, thereby improving the visibility of the lighting device. A lighting device(50) is composed of a light source for emitting the light and a diffusion plate(53) disposed at the front side of the light source and made of transparent or semi-transparent resin material having bubbles for scattering the light, to diffuse the light emitted from the light source over the whole surface, wherein the diameter of the bubble is within a range of 60~700 micrometers. The content rate of the bubbles included in the diffusion plate is 5~35%.

Description

Lighting Device

1 is an exploded perspective view showing an example of the configuration of a conventional advertising device is applied lighting device

Figure 2 is an exploded perspective view of the advertising device is applied lighting device according to an embodiment of the present invention

3 is a cross-sectional view of main parts of the lighting apparatus of FIG.

4A to 4C are views showing modifications of the supporting member of the lighting apparatus shown in FIG.

5 is a sectional view showing the principal parts of another embodiment of a lighting apparatus according to the present invention;

Explanation of symbols on the main parts of the drawings

10: frame 20: window panel

40: advertising sheet 50: lighting device

51: circuit board 52: light emitting diode

53 diffuser plate 54 bubble

55: resin plate for auxiliary diffusion 56: support member

The present invention relates to a lighting device, and more particularly, used as an advertising device such as a billboard, or a lighting device for illuminating an interior, or an lighting device for an interior, and provides a uniform amount of light throughout the entire area. It relates to a lighting device having a transmittance.

Recently, various advertisement devices such as advertisements, billboards, self-emitting advertisement devices, etc., are used for product advertisements or business advertisements of various companies. These advertising devices use a variety of pictures, phrases, photographs, drawings, etc. to increase the visibility of information to buyers, especially those that use lighting devices to properly deliver the desired information at night or low light. It is developed a lot.

1 of the accompanying drawings shows a configuration of a conventional advertising device is applied, the conventional advertising device is a window panel 2 in the form of a transparent panel in front of the frame 1 having a predetermined shape, such as a rectangular It is installed, the advertising sheet (4) is installed on the back of the window panel (2), the lighting device (5) for providing the light toward the front advertising sheet (4) in the rear of the advertising sheet (4) ) Consists of an installed configuration.

The lighting device 5 includes a plurality of light emitting diodes 5a (light emitting diodes) (LEDs) spaced at regular intervals as light sources, and a diffusion plate for diffusing light emitted from the light emitting diodes 5a. 5c). The light emitting diodes 5a are installed on a circuit board 5b such as a PCB.

Therefore, when power is applied to the light emitting diodes 5a through the circuit board 5c, light is emitted through the light emitting diodes 5a, and the emitted light is spread through the diffuser plate 5c so that the front advertising sheet ( 4) is provided.

However, the lighting apparatus used in the conventional advertising apparatus is installed so that the light emitting diodes 5a serving as light sources have a predetermined interval, and the diffusion plate 5c has a simple plate structure, and thus the diffusion degree is low. The portion where 5a) is installed is relatively bright and the portion away from the light emitting diode 5a is relatively dark, so that the entire advertising device cannot provide light of uniform brightness.

If the brightness difference is more than a certain degree, the visibility of the advertisement designed in the advertisement sheet 4 is remarkably degraded, and a problem may occur in that the contents of the advertisement may not be properly delivered.

Therefore, conventionally, in order to solve such a problem of light uniformity reduction, measures such as reducing the number and interval of light emitting diodes and employing light emitting diodes having a wide radiation angle have been devised. In this case, not only the manufacturing cost increases but also the power consumption. Increasingly, structural complexity also increases.

In addition, the diffusion plate used in the conventional lighting device is mostly manufactured by adding polymer particles, such as partially crosslinked inorganic particles, styrene-based or acrylic polymer particles. There is a costly problem. In addition, such a diffuser plate is excellent in light diffusion, but the light transmittance is low, there is a problem that the overall luminance characteristics are low.

In addition, a conventional fluorescent lamp or other lighting device is provided with a light transmissive cover to provide a soft light as the light emitted from the light source is diffused throughout the room, the light transmissive cover is made of simple resin or glass, so the light transmittance is low There is a problem in that it cannot provide light with a uniform amount of light as a whole.

The present invention is to solve the above-mentioned problems, the object of the present invention is to provide a high brightness characteristics with excellent light transmittance, while providing light of uniform brightness over the entire portion of the lighting device at a low cost. To provide a lighting device that can be.

The present invention for achieving the above object, and a light source for emitting light; It is disposed in front of the light source, and made of a transparent or semi-transparent resin material having a bubble having a diameter within the range of 60㎛ ~ 700㎛ for scattering light therein, diffuse the light emitted from the light source to the entire surface It provides a lighting device configured to include a diffuser.

According to the present invention, since the light emitted from the light source of the illumination device is scattered by the bubble having a predetermined size of the diffuser plate, the light is uniformly spread over the entire surface of the diffuser plate, and excellent light transmittance Can be provided. Therefore, by applying such a lighting device, while providing a uniform amount of light over the entire surface of the advertising sheet of the advertising device to provide a high light transmittance, there is an advantage that can improve the brightness characteristics, and thus the visibility.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the lighting apparatus according to the present invention.

Although the lighting apparatus of the present invention described below is applied to an advertising apparatus, the present invention may be applied to various lighting apparatuses, such as a lighting apparatus for illuminating an interior, such as a fluorescent lamp, or an interior lighting apparatus having a specific form.

As shown in Figures 2 and 3, the advertising device to which the illumination device of the present invention is applied is provided with a window panel 20 in the form of a transparent panel in front of the frame 10 having a predetermined shape, such as a rectangle, Advertisement sheet 40 is installed on the back of the window panel 20, the lighting device 50 for providing light toward the front advertising sheet 40 in the rear of the advertising sheet 40 is installed Is done.

The advertisement sheet 40 and the window panel 20 may be formed individually, but may be integrally formed with each other, and the advertisement sheet 40 is directly fixed to the frame 10 without the window panel 20 to the outside. It may also be configured to be exposed.

In addition, the advertising sheet 40 is in the form of a thin film differently coated on the front surface of the secondary diffusion resin plate 55 or diffuser plate 53 constituting the lighting device 50, or a thin cloth or screen However, it may be formed in the form of a rigid plate closely attached to the front surface of the lighting device 50, or may be arranged to be spaced a predetermined distance apart. In addition, the advertisement device may be configured by directly printing the letters or drawings for the advertisement on the resin plate 55 or the diffusion plate 53 of the lighting device 50 without using the advertisement sheet.

The lighting device 50 includes at least one circuit board 51 installed on the frame 10 at regular intervals and a plurality of light emitting diodes 52 disposed on the circuit board 51 at regular intervals to emit light. It consists of a light source consisting of, a rectangular plate-shaped diffuser plate 53 disposed between the light source and the advertisement sheet 40, and a secondary diffusion resin plate 55 disposed on the front surface of the diffuser plate 53. .

The circuit board 51 of the light source may be made of a single body, but may be configured using a plurality of circuit boards having an elongated strip shape as shown in FIG. 1.

The diffusion plate 53 is made of a transparent or translucent light transmissive material, such as polycarbonate (PC), polymethylmethacrylate (PMMA), acrylic, epoxy, polyethylene terephthalate (PET), or melamine resin, and internally for scattering light Bubbles 54 of a predetermined size are formed.

The bubble 54 may be formed by extrusion or injection when the diffusion plate 53 is manufactured, or may be formed by foam molding such as foam extrusion or foam injection.

The number and size (diameter) of bubbles 54 per unit volume formed in the diffusion plate 53 should be formed in an appropriate number and size in consideration of diffusibility and permeability. That is, when the number of bubbles 54 per unit volume of the diffusion plate 53 is too large, light may not be transmitted well and light transmittance may be lowered. On the contrary, when the number of bubbles 54 per unit volume of the diffusion plate 53 is too small, light scattering may be low and diffusion may not be performed properly.

In addition, when the size of the bubble 54 is too small, the light diffusivity may be good, but the light transmittance is significantly lowered, resulting in a lowering of the overall luminance characteristics.

Accordingly, the present invention is limited to the size of the bubble 54 in the range of 60㎛ ~ 700㎛ to satisfy both the light transmittance and the light diffusion. When the size of the bubble 54 is 700 µm or more, the light transmittance is improved, but the light diffusivity is lowered. When the size of the bubble 54 is smaller than 60 µm, the light diffusivity is good but the transmittance of the light is lowered and the luminance is lowered. Thus, when the size of the bubble 54 is small and the transmittance is lowered, the luminance is lowered. Therefore, there is a problem that the diffusion plate 54 cannot be applied to an illumination device such as an advertisement board or a lamp cover. In general, in the advertising industry, outdoor billboards are known to be suitable when the illuminance is at least 1500 lux.

In addition, when the size of the bubble 54 is 60 μm or more, the general person can visually observe the bubble 54 without the help of a device such as a microscope. When the bubble 54 is smaller than this, the bubble 54 ), It is difficult to check with the naked eye, and when the size of the bubble 54 is 60 µm or less and the bubble content is 5% or more, the entire diffuser plate 53 has a color close to gray instead of white. ) Can be used for high-precision diffusion, such as a light guide plate, but is not suitable for use in advertising billboards, lamp covers, interior devices, and the like. That is, when the diffusion plate 53 is gray, it affects the intrinsic color of the advertisement sheet of the advertisement apparatus, and the color reproduction rate is lowered, which is not suitable for applying to the advertisement apparatus, the lamp cover, or the interior apparatus. .

Table 1 below is an experiment of the methyl methacrylate (PMMA) resin by impregnating carbon dioxide gas at supercritical pressure and then reducing the pressure to foam the nuclei of bubbles generated at high temperature (100 ° C.) and cooling them with diffusion plates. One result is shown. The light source used in the experiment was configured by arranging the light emitting diodes (LED) having a radiation angle of 120 degrees and 3000 mcd (millicella) of SMD 2CHIP in three horizontally x three vertically at 50 mm intervals. Then, a light panel having a height of 50 mm is manufactured, and a PCB in which the light emitting diodes are installed is installed therein, the illuminance of the upper end of the light panel is adjusted to 3600 lux, and then a diffuser plate is placed at this point. Etc. were measured.

Particle Size (Micro) 60 ~ 700 (㎛) 1 to 50 (㎛) Included flow rate (%) 4 20 46 18 Illuminance value (lux) 3492 3312 2268 2160 Total light transmittance (%) 97 92 63 60 Light diffusion lowness good Very good Very good Light rug Translucent White White Light gray Ad image installation Illuminance value (lux) 2270 2152 1474 1404 Check light source Confirm Not OK Not OK Not OK Availability for advertising can not be used Available can not be used can not be used

As can be seen in Table 1, when the size of the bubbles contained in the diffusion plate 53 is 60 ~ 700㎛ has a good roughness of more than 3300 lux (bubble) at 4% and 20% of the bubble content, respectively, bubbles When the size was 1 to 50 µm (bubble content 18%), the roughness was significantly reduced to 2160.

And when the bubble size is 60 ~ 700㎛, the total light transmittance was 97% and 92% at 4% and 20% of the bubble content, respectively. It can be seen that the transmittance is significantly reduced to 60%.

In addition, when experimenting with the advertising image on the diffuser plate, if the bubble size is 60 ~ 700㎛ both in the advertising industry of 2270 lux and 2152 lux in the bubble content of 4% and 20% respectively Although the illuminance value was well above the required 1500 lux standard for outdoor advertisements, the bubble size was 1400 lux lower than the 1500 lux standard for outdoor advertisements. .

As can be seen from these experimental results, the diffusion plate 53 of the present invention has excellent luminance characteristics and light transmittance at a bubble content of approximately 4-20% when the bubble size is 60 ~ 700㎛.

However, if the bubble size of the diffusion plate is in the range of 60 ~ 700㎛ but the bubble content is less than 4%, light diffusion is low, and the color is also close to translucent, so when the advertisement image is installed, the light source is visible to the outside and the light source can be checked. Therefore, it becomes unsuitable as a billboard. Therefore, in order to apply the diffusion plate to an advertisement device such as an advertisement board, the size of the bubble is preferably 5% or more in the range of 60 to 700 μm.

More preferably, when the diffuser plate is applied to an advertisement device such as an advertisement plate, the bubble of the diffuser plate has a size of 60 to 700 µm, and the bubble content rate is most preferably in the range of about 10% to 20% in this size range. .

On the other hand, since the diffuser plate having a bubble size of 1 to 50 μm has a very good light diffusivity, it is advantageous when applied to a light guide plate of a liquid crystal display device, but is not suitable as an advertisement device, a lighting lamp, or an interior device.

As described above, the diffusion plate 53 according to the present invention showed light transmittance of about 90% or more and excellent roughness value, but the diffusion plate with too small bubble particles or too large bubble content has low light transmittance and low illuminance. It can be seen that it is not suitable for the back.

In addition, light guide plates for general liquid crystal display devices without bubbles have a light transmittance of about 70 to 75%, and because inorganic particles such as titanium oxide are used, they are heavy and expensive, and thus they are difficult to be applied to large billboards or lamps. .

However, the diffuser plate of the present invention is reduced in weight due to the bubble 54, the production cost is also low and easy to manufacture large, can satisfy both the light diffusion and light transmittance.

In addition, it is preferable that the bubbles 54 formed in the diffusion plate 53 have different sizes from those arranged in the front and those arranged in the rear. For example, it is preferable that the bubbles 54 arranged behind the diffuser plate 53 have a smaller size than the bubbles 54 arranged in front of the diffuser plate 53. In this case, the bubble 54 of the diffuser plate 53 can be visually checked from the outside, and when light is provided from the light source, the light traveling toward the diffuser plate 53 easily passes while meeting the large bubble 54. Therefore, it is possible to provide excellent luminance characteristics.

In the case where the average size of the bubbles 54 arranged in front of the diffuser plate 53 and the bubbles 54 arranged in the rear is different, it has been confirmed that the permeability is further improved without decreasing the diffusivity.

On the other hand, the auxiliary diffusion resin plate 55 is preferably made of white, in addition to other colors such as yellow or yellow, it may be made of a light-transmissive resin material such as acrylic.

The auxiliary diffusion resin plate 55 may be formed separately from the diffusion plate 53, but alternatively, the auxiliary diffusion resin plate 55 may be integrally formed with the diffusion plate 53 by a double injection molding method.

In addition, when the advertising apparatus is enlarged and the diffusion plate 53 is made large, the deformation degree of the diffusion plate 53 is increased accordingly. Therefore, the diffusion plate 53 supports the diffusion plate 53 at the rear surface of the diffusion plate 53. It is preferable to prevent the plate 53 from being deformed. In the present invention, by forming a support member 56 for supporting the diffuser plate 53 with respect to the circuit board 51 between the diffuser plate 53 and the circuit board 51, the diffuser plate 53 is a light source of the rear Suggest ways to avoid bending

When the end of the support member 56 is in full contact with the diffuser plate 53, the light is not diffused completely in the area in which the support member 56 is in contact, so that this part is shaded when viewed from the outside. This can happen.

Accordingly, as shown in FIG. 4A, the support member 56 may be formed so that the tip portion of the support member 56 is slightly separated by the diffusion plate 53. Alternatively, as shown in FIGS. 4B and 4C, the support member 56 may be formed. It is preferable to minimize the contact area between the support member 56 and the diffusion plate 53 by forming the tip portion of the 56 in a curved shape or the tip portion in the form of a small pin or protrusion.

In addition, the support member 56 is preferably located at regular intervals between the light emitting diodes 52.

Meanwhile, the distance between the diffusion plate 53 and the circuit board 51 may be determined by the radiation angle of the light emitting diode 52 as a light source.

Specifically, the radiation angle of a typical light emitting diode 52 is about 70 degrees, and when the light emitting diode having such a radiation angle is used, the distance between the diffusion plate 53 and the circuit board 51 is preferably about 70 mm. Do.

However, when the emission angle of the light emitting diode 52 is larger than that, since the light diffusing degree of the light emitting diode 52 is good, the distance between the diffusion plate 53 and the circuit board 51 is smaller than 70 mm, or as shown in FIG. 5. It could be configured to be nearly concatenated as it was.

As illustrated in FIG. 5, when the circuit board 51 and the diffuser plate 53 are connected to each other, a plurality of grooves 53a in which the light emitting diodes 52 are accommodated are provided on the rear surface of the diffuser plate 53. It is preferably formed in the form of a channel.

The lighting apparatus according to the present invention configured as described above operates as follows.

When power is applied to each of the light emitting diodes 52 through the circuit board 51, light is emitted through the light emitting diodes 52. The light emitted from the light emitting diodes 52 enters into the diffuser plate 53, is scattered by bubbles 54 of the diffuser plate 53, and spreads to the entire surface of the diffuser plate 53. Done.

The light spread to the front by the diffusion plate 53 passes through the secondary diffusion resin plate 55 to be secondarily diffused to achieve a more uniform light uniformity, and then is emitted to the outside through the advertisement sheet 40 so as to The user can view the advertisement design of the advertisement sheet 40.

On the other hand, although the light emitting diode 52 (LED) is used as the light source in the above-described embodiment of the lighting device, a fluorescent lamp or a neon lamp may be used.

In addition, although the above-described lighting apparatus is applied to an advertising apparatus such as an advertisement board, the lighting plate according to the present invention is different from that of a lamp cover such as a fluorescent lamp cover or a stand cover, or a specific light source present therein. The case may be applied to a case of an interior device having an artistic shape such as a person or an animal.

The lighting apparatus for the advertising apparatus of the present invention may be variously implemented and modified within the spirit and scope of the invention defined by the claims of the present invention in addition to the above-described embodiments.

As described above, according to the present invention, since the light emitted from the light source of the lighting device is scattered by the bubbles of the diffuser plate, the light is uniformly spread over the entire surface of the diffuser plate, and the light source has a high light transmittance. It transmits the light emitted from it. Therefore, the uniform amount of light is provided over the entire surface of the advertisement sheet of the advertisement device, and the excellent brightness characteristics are provided to improve the visibility of the advertisement.

Claims (8)

A light source for emitting light; It is disposed in front of the light source, and made of a transparent or semi-transparent resin material having a bubble having a diameter within the range of 60㎛ ~ 700㎛ for scattering light therein, diffuse the light emitted from the light source to the entire surface Lighting device comprising a diffuser to make. The illuminating device according to claim 1, wherein the content of bubbles contained in the diffusion plate is 5 to 35%. The illuminating device according to claim 1, wherein the bubble of the diffusion plate becomes larger or smaller in an average size from the light source direction toward the opposite direction. The lighting apparatus of claim 1, wherein the light source comprises a circuit board disposed behind the diffusion plate and light emitting diodes (LEDs) arranged on the circuit board. The lighting apparatus according to claim 1, further comprising a support member disposed between the light source and the diffusion plate to prevent the diffusion plate from bending toward the rear light source. The lighting apparatus according to claim 1, further comprising an auxiliary diffusion resin plate disposed on a front surface of the diffusion plate and made of a white or colored light transmitting resin material. 7. The lighting apparatus according to claim 6, wherein the auxiliary diffusion resin plate is formed integrally with the diffusion plate. 7. The lighting apparatus according to claim 6, wherein the auxiliary diffusion resin plate is formed separately from the diffusion plate.

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